In the virtual world you can look but not really touch, at least not yet.

As 6,800 multimedia experts from 75 countries gather in Los Angeles for the annual Siggraph Convention, it is becoming clear virtual reality is becoming chillingly real.

Imagine being able to smell the disgusting breath of dinosaurs in a future version of Jurassic Park and feel the ground shake as they approach.

This does not seem so far fetched given new research being presented at the international conference.

Seeing isn't quite believing

The look of VR is getting slicker every day. Joystick trips are possible through virtual landscapes and they are impressive.

Siggraph facts

Anticipated total attendance: 40,000

Anticipated international attendance: 6,800 from 75 countries

Anticipated exhibitors: 300 companies

What are lacking are the smells and sensations of the real world. But so-called haptic, or touch technologies being developed at the University of Tokyo by Takuya Nojima hint at what is to come.

Mr Nojima's research allows something as delicate as the boundary between two liquids - oil and water, perhaps - to be touched.

His ambitions for the technology may be lofty but it is easy to speculate on more mundane future applications for this, too.

A VR cookery course, for instance, where haptics and a dash of smell science help demonstrate the feel of a ripe mango, or how a charentais melon should smell when it is good to eat.

How shall we play today?

From its origins in 1969 as the Association for Computing Machinery's Special Interest Group on Computer Graphics and Interactive Techniques, Siggraph has grown out of all recognition.

The evolution of computer graphics can best be understood as part of the...evolution of human intelligence and its relationship to the natural world

Danny Hillis, Applied Minds

For the past 27 years, the world's leading video games manufacturers have joined animators, artists and video directors to show off their best at Siggraph.

This year their impact will be felt even more keenly among cinemagoers, as their technical and artistic triumphs have resulted in a stable of virtual film stars that teenagers could easily fall for.

Supercomputer pioneer and former Disney Vice President Danny Hillis is one of those whose work has made all this possible.

Now with the firm Applied Minds, Mr Hillis is a man with a passion for multimedia.

"The evolution of computer graphics can best be understood as part of the...evolution of human intelligence and its relationship to the natural world," he says in his keynote address to Siggraph.

Dog eat dog

On the subject of evolution, Bill Tomlinson's Alpha Wolf installation, developed at MIT's Media Labs, is a chance to experience its principles at first hand.

It allows users to interact socially with a pack of autonomous virtual wolves on screen.

Whether your interest is in the biological principles of natural selection and the ecological threat to wolves in the wild, or you are just a stressed out executive struggling to pull together an unruly office team, this package is a real education.

It seems to sum up what Siggraph is all about this year.

As the 40,000 attendees jostle for a sight of the latest big thing, it is the convergence of multimedia technology and hard science that is likely impress the most.

Siggraph 2001 runs from 12 to 17 August at the Los Angeles Convention Center